This lens is awsome to use, almost a prime killer, although on the bulky side. Also, can create some "onion rings" effects in certain conditions that can undesirable. But overal a very solid lens. Very good build quality and crazy fast autofocus for the size of the lens.
It is an amazing do-it-all lens that I am super pleased with. Having f2 in a zoom lens makes it perfect for low-light wedding and event photography. This is a great middle ground between fast primes and versatile zoom lenses. The only downside for me is the heavy distortion at 28 mm. Hopefully soon there will be a lens profile correction for lightroom and some in camera distortion fix for video.